Letter from E H [Edward Hutchinson] Synge, Knockroe, Dundrum, Co Dublin, to Sir Joseph Larmor Synge will see about having the notebooks sent over to Larmor, but he may have to bring them over himself. He is not convinced by Larmor's belief that [William Rowan] Hamilton's researches on the Dynamics of Light were unimportant. He transcribes a letter from Hamilton to [George Biddell] Airy of 23 September 1836 and comments upon [Augustin Louis] Cauchy's obsolete theory. Synge discusses his own acquaintance with the theory of light from 'some years ago', and he thinks there is a strong case for Hamilton's theory to be examined and compared with [Augustin Jean] Fresnel's. This relates to Hamilton's early work, and Synge describes Hamilton's later work of 1839-1840, noting a letter to [John Frederick William] Herschel. He has a strong feeling that something of importance has been missed. In a postscript, Synge asks if in the mechanics of Hamilton's theory, there might be grounds for the supposition that light travels in 'quanta'. 22 September 1923